ITHACA, N.Y. — The highly invasive aquatic plant, hydrilla verticillata, known commonly as “hydrilla” or “water thyme” was detected last week in the Cayuga Inlet by Cornell staff.
Hydrilla is an aggressively growing plant that can displace native plants, clog waterways and interfere with boating, fishing and swimming.
To date, hydrilla appears to be localized in the Cayuga Inlet, with no evidence that it has yet rooted in Cayuga Lake. It has long, slender stems that can grow underwater to lengths of up to 25 feet.
If left unchecked, hydrilla can grow up to an inch per day, creating a thick mat of vegetation when it reaches the water’s surface. Hydrilla quickly shades out other aquatic plants, displacing native species.
This is the first detection of hydrilla in upstate New York waters, and the risk of it spreading to Cayuga Lake and other regional water bodies is substantial. Fragments of the plant, which are easily caught and transported by boats and boat trailers, can sprout roots and establish new populations.
Fragments also float and are capable of dispersing via wind and water currents. Native to Asia, hydrilla was first introduced to the United States in the 1950s when the contents of an aquarium were dumped into a waterway in Florida.
It has since spread from Florida to Maine and into a number of Western states. It is found worldwide on every continent except Antarctica. Federal, state and local municipal officials along with biologists from Cornell are gathering Aug. 19 to discuss rapid response and control options.
Recreational users of Cayuga Inlet are urged to employ clean boating practices to prevent the further spread of hydrilla and other aquatic invasive species. Remove any plants, mud or debris from boats or equipment that came in contact with water.
Drain any water from boats before leaving a launch area. Clean and dry anything that came in contact with water including boats, trailers, gear, clothing and dogs. Never release plants, fish or bait into a body of water unless they came out of that particular body of water.
For more information about hydrilla and other invasive species, visit Cornell Cooperative Extension’s New York Invasive Species Clearinghouse at